Tin (IV) chloride catalysed synthesis of di(indolyl)methanes during electrophilic substitution of indoles and 2-methyl indoles

An efficient methodology has been developed for the synthesis of di(indolyl)methanes in moderate to good yields during the study of the reactions of indole and 2-methyl indole using a series of aliphatic ketones in the presence of stannic chloride. It appears worth mentioning that with 2-methyl indole and acetone and ethyl methyl ketone the highly “elusive” indolylcarbinols, the postulated intermediates in the synthesis of di(indolyl)methanes, have been isolated

[3+2] Cycloadditions. Part XXXIII. Selective cycloadditions of C-(1-naphthyl)-N-methyl nitrone and C-phenyl-N-benzyl nitrone to α,β-unsaturated carbonyl compounds1,2

488-501[3+2] Cycloadditions [32CA] involving nitrones as 1,3-dipolar species to alkenes yield isoxazolidines, which on further transformations can be converted to naturally occurring bioactive compounds. Thus the 32CA route provides conversion of simple natural products to more complex natural occurring bioactive nitrogen heterocycles, and close analogues. The present work deals with 32CA between the nitrones C-(1-naphthyl)-N-methyl nitrone and C-phenyl-N-benzyl nitrone to α,β-unsaturated carbonyl compounds as dipolarophiles, viz. arylidene malonate esters, methyl cinnamate and benzylidene acetophenone (chalcone). Methyl cinnamate is a naturally occurring compound, while the chalcone scaffold is present in several natural products. Structure elucidation of the generated cycloadducts have been achieved by means of detailed spectroscopic and XRD studies. All the cycloadditions investigated occurr regioselectively to yield tetra/penta-substituted isoxazolidines, where the carbonyl group(s) are situated at the 4-position of the isoxazolidine ring. DFT computations including optimised geometries, FMO energies, electronic chemical potentials, chemical hardness, chemical softness and reactivity indices of a number of the reactants have been calculated at DFT/B3LYP/6-31++G(d,p) level of theory. The calculated reactivity indices have been used to analyse the 32CAs studied and to predict the regioselectivities; the predictions are in excellent accord with the experimental results

An Overview of the Genus Nardostachys

Nardostachys jatamansi, a medicinally important herb of Nepalese origin, has been used for centuries in the Ayurvedic and Unani systems of medicine. In combination with Marsilea minuta it is being used as an antistress and anticonvulsant drug and also finds use in the treatment of epilepsy. Recently, it has been reported that N. jatamansi, which plays an important role in protecting from cerebral ischemia and liver damage, is also used for the treatment of osteoporosis and hypercalcemia. The other member of the genus Nardostachys, N. chinensis, possesses antifungal and antimalarial properties. It is also used in the treatment of skin dysfunction. A short summary of the chemical constituents of the two species along with their physical and biological properties is reported

N-(4-Methylphenyl) Benzenepropanamide - the First Isolated Amide From the Genus Paederia

Investigation of the stem of Paederia foetida (Rubiaceae) resulted in the isolation and characterization of N-(4-methylphenyl)-benzopropanamide, which was hitherto unknown as a natural product This is the first report of an amide for the genus Paederia

1,3-Dipolar cycloadditions: Part nt-Cyc1oaddition of 1-pyrroline 1-oxide to 1-cinnamoyl piperidine and 1-(4'-chlorocinnamoyl) piperidine

15-2

Development of quality standards of Triphala Kwatha churna with its ingredients through HPTLC and mass spectroscopy

113-119In recent years there has been rapid growth in the field of herbal medicine. Drugs belonging to Asian traditional systems of medicine are accepted universally only after standardisation. It is therefore, very important to develop essential techniques for standardisation of herbal drugs. The present study has focused on development of quality standards of Triphala Kwatha churna under WHO/API guidelines along with HPTLC and mass spectroscopy. This polyherbal Kwatha churna is used to treat constipation and other gastric disorders. In this study, an in-house prepared Triphala Kwatha churna was botanically and chemically standardised by HPTLC and mass spectroscopic studies with the reference standard gallic acid. The botanical standardisation of the above formulation was done by evaluation of macroscopic and microscopic studies of the powder formulation along with its ingredients. Physicochemical parameters like LOD, ash value, acid insoluble ash, water and alcohol extractives were determined. Safety parameters, viz., heavy metals, microbial content, specific pathogens, pesticide residue and aflatoxins detection have been also estimated. The results obtained in the present study defining quality control parameters help to develop the quality standards of Triphala Kwatha churna formulation. The HPTLC fingerprint profiling of the formulation along with its ingredients complies with the reference standards gallic acid. This observation is also found in Mass Spectroscopic study of the methanolic extract of the formulation with this reference standard. Preliminary phytochemical screening test revealed the presence of bioactive constituents including phenols, flavonoids, tannins and carbohydrate

1,3-Dipolar cycloadditions: Part III-Cycloaddition of C,N-diarylnitrones to N-cinnamoylpiperidines

105-11

Tin (IV) chloride catalysed synthesis of di(indolyl)methanes during electrophilic substitution of indoles and 2-methyl indoles

697-702An efficient methodology has been developed for the synthesis of di(indolyl)methanes in moderate to good yields during the study of the reactions of indole and 2-methyl indole using a series of aliphatic ketones in the presence of stannic chloride. It appears worth mentioning that with 2-methyl indole and acetone and ethyl methyl ketone the highly “elusive” indolylcarbinols, the postulated intermediates in the synthesis of di(indolyl)methanes, have been isolated

Unfolding of an amazing rearrangement by NMR spectroscopy during the study of the electrophilic substitution of indole with acetone using boron trifluoride etherate

949-950During the study of the electrophilic substitution of indole with acetone in the presence of boron trifluoride etherate two interesting products (I) and (II) have been obtained. Compound (I) is found to be highly unstable in deuterochloroform. The study of this instability has led to discovery of an amazing rearrangement of (I) to (II) in deuterochloroform and in acid medium

1,3-dipolar cycloadditions. Part XX. DFT study of the configuration and conformation of C-aryl-N-phenyl nitrones and their reactivities as 1,3-dipoles to methyl and ethyl crotonates

1444-1452The preferred configurations and conformations of C-aryl-N-phenyl nitrones have been predicted theoretically by detailed comparison of DFT/B3LYP/6-311+G(2d,p) calculated gauge invariant atomic orbital nuclear magnetic shielding tensors and experimentally recorded chemical shift values. The frontier molecular orbital energies, electronic chemical potentials, chemical hardness, chemical softness and global electrophilicity indices of C-aryl-N-phenyl nitrones have been calculated at DFT/B3LYP/ 6-31+G(d,p) level of theory. Condensed Fukui functions and local electrophilicity indices have been computed to characterize the reactive sites and predict the preferred interactions of C-aryl-N-phenyl nitrones to methyl and ethyl crotonates. The softness matching indices have been evaluated to determine the regioselectivity of the cycloaddition reactions. The theoretical predictions were found to be in complete agreement with the experimental results implying that the DFT based reactivity indices correctly predict the regioselectivities of 1,3-dipolar cycloadditions of C-aryl-N-phenyl nitrones to methyl and ethyl crotonates